scholarly journals Recovery of valuable metals from waste printed circuit boards using organic acids synthesised by Aspergillus niveus

2021 ◽  
Author(s):  
Santhosh Krishnamoorthy ◽  
Gnanasekaran Ramakrishnan ◽  
Balaji Dhandapani
Keyword(s):  
Organic Acids ◽  
Printed Circuit Boards ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Aspergillus Niveus ◽  
Waste Printed Circuit Boards ◽  
Valuable Metals

Supercritical CO2-induced alteration of a polymer–metal matrix and selective extraction of valuable metals from waste printed circuit boards

2020 ◽  
Vol 22 (20) ◽  
pp. 7080-7092
Author(s):  
Peng Peng ◽  
Ah-Hyung Alissa Park
Keyword(s):  
Metal Matrix ◽  
Supercritical Co2 ◽  
Printed Circuit Boards ◽  
Selective Extraction ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Valuable Metals ◽  
Polymer Metal

Supercritical CO2-induced treatment of heterogeneous waste printed circuit boards resulted in selective recoveries of Au, Ni and Cu.

scholarly journals Extraction of Copper and Zinc from Waste Printed Circuit Boards

Recycling ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 36 ◽  
Author(s):  
Ayorinde Emmanuel Ajiboye ◽  
Folorunsho Emmanuel Olasehinde ◽  
Ojo Albert Adebayo ◽  
Olubode John Ajayi ◽  
Malay Kumar Ghosh ◽  
...  
Keyword(s):  
Printed Circuit Boards ◽  
Selective Extraction ◽  
Leach Solution ◽  
Economic Resources ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Valuable Metals ◽  
Extraction Selectivity ◽  
Cu And Zn

The recovery of valuable metals from waste printed circuit boards (WPCBs) is crucial in order to harness their economic resources, and prevents potential environmental contamination. However, selective extraction of Cu and Zn, and the co-extraction of other metals as impurities at ambient temperature using selected lixiviants such as HCl, H2SO4, HNO3, trifluoromethanesulfonic acid (TFMS), NaOH, and mixtures of NaCl and CuCl2 was studied. It is shown that the extraction efficiencies of all the metals increased with increases in lixiviant concentrations. High selectivity of Cu and Zn toward Fe were achieved in dilute H2SO4, HNO3, TFMS, and 0.5 M NaCl + 0.1 M CuCl2, and low dissolution of Pb (<5%) was observed in all H2SO4 lixiviants. Almost 100% Zn extraction using NaOH lixiviants without trace of other metals was achieved. Therefore, 0.5 M NaCl + 0.5 M CuCl2, 1.0 M HNO3, 0.5 M H2SO4, and 1.0 M TFMS showed high extraction selectivity toward Cu and Zn with low chemical consumption, and produced pregnant leach solution rich in Cu and Zn, as well as residue containing Fe, Ni, and other metals.

scholarly journals Hydrometallurgical Treatment of Waste Printed Circuit Boards: Bromine Leaching

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 462 ◽  
Author(s):  
Hao Cui ◽  
Corby Anderson
Keyword(s):  
Printed Circuit Boards ◽  
Sodium Concentration ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Inorganic Acids ◽  
Valuable Metals ◽  
Bromine Concentration ◽  
Hydrometallurgical Treatment ◽  
Solid Liquid

This paper demonstrates the recovery of valuable metals from shredded Waste Printed Circuit Boards (WPCBs) by bromine leaching. Effects of sodium bromide concentration, bromine concentration, leaching time and inorganic acids were investigated. The most critical factors are sodium concentration and bromine concentration. It was found that more than 95% of copper, silver, lead, gold and nickel could be dissolved simultaneously under the optimal conditions: 50 g/L solid/liquid ratio, 1.17 M NaBr, 0.77 M Br2, 2 M HCl, 400 RPM agitation speed and 23.5 °C for 10 hours. The study shows that the dissolution of gold from waste printed circuit boards in a Br2-NaBr system is controlled by film diffusion and chemical reaction.

scholarly journals Characteristics of Metals Leached from Waste Printed Circuit Boards Using Acidithiobacillus ferrooxidans

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 224
Author(s):  
Jinsung An
Keyword(s):  
Acidithiobacillus Ferrooxidans ◽  
Printed Circuit Boards ◽  
Cost Effective ◽  
Low Grade ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Iron Oxidizing Bacteria ◽  
Valuable Metals ◽  
Leaching Characteristics

The aim of this study was to compare leaching characteristics of metals from printed circuit boards (PCBs), taken from waste electrical and electronic equipment in the presence and in the absence of the iron-oxidizing bacteria, Acidithiobacillus ferrooxidans. A. ferrooxidans not only increases the leached concentration of Cu from the PCBs, but also inhibits the components of the 0K medium and leached Cu from forming precipitates such as libethenite (Cu2(PO4)(OH)), thereby assisting Cu recovery from the PCBs. In addition, the leached concentration of Pb from PCBs decreased in the presence of A. ferrooxidans, due to Pb forming amorphous precipitates. It is expected that Pb is not highly toxic to A. ferrooxidans. Consequently, A. ferrooxidans can be used as a cost-effective and environmentally friendly way to leach out valuable metals from PCBs as low-grade urban ore.

Evaluating waste printed circuit boards recycling: Opportunities and challenges, a mini review

2017 ◽  
Vol 35 (4) ◽  
pp. 346-356 ◽  
Author(s):  
Abhishek Kumar Awasthi ◽  
Gabriel Ionut Zlamparet ◽  
Xianlai Zeng ◽  
Jinhui Li
Keyword(s):  
Large Scale ◽  
Printed Circuit Boards ◽  
Review Article ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Valuable Metals ◽  
Rapid Generation

Rapid generation of waste printed circuit boards has become a very serious issue worldwide. Numerous techniques have been developed in the last decade to resolve the pollution from waste printed circuit boards, and also recover valuable metals from the waste printed circuit boards stream on a large-scale. However, these techniques have their own certain specific drawbacks that need to be rectified properly. In this review article, these recycling technologies are evaluated based on a strength, weaknesses, opportunities and threats analysis. Furthermore, it is warranted that, the substantial research is required to improve the current technologies for waste printed circuit boards recycling in the outlook of large-scale applications.

Selective Leaching of Valuable Metals from Waste Printed Circuit Boards

2003 ◽  
Vol 53 (7) ◽  
pp. 897-902 ◽  
Author(s):  
Chi Jung Oh ◽  
Sung Oh Lee ◽  
Hyung Sik Yang ◽  
Tae Jun Ha ◽  
Myong Jun Kim
Keyword(s):  
Printed Circuit Boards ◽  
Circuit Boards ◽  
Selective Leaching ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Valuable Metals

Research on the Recycling of Valuable Metals from Waste Printed Circuit Boards by Eddy Current Separation

2010 ◽  
Vol 113-116 ◽  
pp. 367-371 ◽  
Author(s):  
Jing Feng He ◽  
Ya Qun He ◽  
Wen Sheng Ge ◽  
Chen Long Duan ◽  
Xiao Bing Wu
Keyword(s):  
Eddy Current ◽  
Printed Circuit Boards ◽  
Physical Mechanism ◽  
Separation Efficiency ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Orthogonal Experiments ◽  
Valuable Metals ◽  
Concentrate Grade

On the basis of introducing the latest research status of processing methods of waste printed circuit boards, the physical mechanism of eddy current separation was explained, and the component configuration of eddy current separator was described. A series of single-factor and orthogonal experiments were carried out to prove the separation effect of multiple metals with eddy current separator. The result indicates that the separation efficiency of above 92.0% and concentrate grade of above 95.0% can be obtained in the recycling of aluminum and brass with the delivery rate of 20~40%, rotate speed of rotor of 5~15Hz and belt speed of 7~9Hz.

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